Heat exchanger

ABSTRACT

A heat exchanger is provided and includes a frame defining a volumetric body with substantially flat upper and lower sides, heat exchange elements disposed within an interior of the body, sorbent material disposed among the heat exchange elements within the interior of the body, retainer screens disposed at upper and lower sides of the heat exchange elements and sorbent material and structural foam layers supportively disposed between the retainer screens and the substantially flat upper and lower sides to absorb loading applied to the retainer screens.

FEDERAL RESEARCH STATEMENT

This disclosure was developed in part in accordance with Navy contractN65540-11-C-0015. The government has certain rights to this invention

BACKGROUND OF THE INVENTION

The subject matter disclosed herein relates to a heat exchanger and to aheat exchanger assembly.

Sorbent canister heat exchangers may be employed in various applicationsincluding, but not limited to, air purifying systems for mannedspacecraft and submarines. Such systems remove carbon dioxide fromrecirculated air so that the air can be re-used for onboard personnelwithout the need for refitting or repeated resurfacing (as the case maybe). When in use, the sorbent canister heat exchangers flow a coolantabout a sorbent material such that the sorbent material is maintained ata temperature at which the sorbent material absorbs and desorbs carbondioxide.

Since space is at a premium on manned spacecraft and submarines, it isoften necessary to design sorbent canister heat exchangers to be assmall and compact as possible. In these cases, it is often seen thatcanisters with flat surfaces provide for the most compact design.However, when the canisters are exposed to external loading from, forexample, depth charge shock waves or external pressure, the flatsurfaces are prone to deformation that is transmitted to the relativelystructurally weak heat exchange elements in the canister interiors. Thisleads to damage and possible failure of the canisters.

BRIEF DESCRIPTION OF THE INVENTION

According to one aspect of the invention, a frame defining a volumetricbody with substantially flat upper and lower sides, heat exchangeelements disposed within an interior of the body, sorbent materialdisposed among the heat exchange elements within the interior of thebody, retainer screens disposed at upper and lower sides of the heatexchange elements and sorbent material and structural foam layerssupportively disposed between the retainer screens and the substantiallyflat upper and lower sides to absorb loading applied to the retainerscreens.

According to another aspect of the invention, a heat exchanger isprovided and includes a frame defining a volumetric body withsubstantially flat upper and lower sides, heat exchange elementsdisposed within the body and including a tubular element through which afirst medium is directable and fins, the fins being orientedperpendicularly with respect to the tubular element, sorbent materialdisposed among the fins within the interior of the body, retainerscreens disposed at upper and lower sides of the heat exchange elementsand sorbent material and structural foam layers supportively disposedbetween the retainer screens and the substantially flat upper and lowersides to absorb loading applied to the retainer screens.

According to yet another aspect of the invention, a heat exchangerassembly including multiple heat exchangers that each include a framedefining a volumetric body with substantially flat upper and lower sidesthat are each configured to register with a complementary side of anadjacent heat exchanger, heat exchange elements disposed within the bodyand including a tubular element through which a first medium isdirectable and fins, the fins being oriented perpendicularly withrespect to the tubular element, sorbent material disposed among the finswithin the interior of the body, retainer screens disposed at upper andlower sides of the heat exchange elements and sorbent material andstructural foam layers supportively disposed between the retainerscreens and the substantially flat upper and lower sides to absorbloading applied to the retainer screens.

These and other advantages and features will become more apparent fromthe following description taken in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWING

The subject matter, which is regarded as the invention, is particularlypointed out and distinctly claimed in the claims at the conclusion ofthe specification. The foregoing and other features, and advantages ofthe invention are apparent from the following detailed description takenin conjunction with the accompanying figures in which:

FIG. 1 is an exploded perspective view of a heat exchanger;

FIG. 2 is a perspective view of the heat exchanger of FIG. 1 asassembled;

FIG. 3 is a perspective view of a heat exchanger assembly;

FIG. 4 is an enlarged perspective view of an interior of the heatexchanger of FIG. 1; and

FIG. 5 is an enlarged perspective view of heat exchange elements of theheat exchanger of FIG. 1.

The detailed description explains embodiments of the invention, togetherwith advantages and features, by way of example with reference to thefigures.

DETAILED DESCRIPTION OF THE INVENTION

With reference to FIG. 1, an exploded view of a heat exchanger 10 isprovided and with reference to FIG. 2, a perspective view of the heatexchanger 10 as assembled is provided. As shown in FIGS. 1 and 2, theheat exchanger 10 includes a frame 20, heat exchange elements 40,sorbent material 60 and structural partition walls 80. The frame 20 isformed to define a volumetric body 21 that may be substantiallyrectangular, for example, with longitudinal end faces 22 and 23,sidewalls 24 and 25 and substantially flat upper and lower sides 26 and27. The end faces 22 and 23 and possibly the sidewalls 24 and 25 may beformed to define through-holes 30 by which air is permitted to enter aninterior 210 of the volumetric body 21. With reference to FIG. 3, theheat exchanger 10 may be disposed in a heat exchanger assembly 100 inwhich multiple heat exchangers 10 are disposed in a substantiallyvertical column with complementary upper and lower sides 26 and 27 ofadjacent heat exchangers 10 abutting one another.

With reference to FIG. 4, the upper side 26 has a substantially flatexterior surface 261 and ribs 35. The ribs 35 are oriented substantiallyin parallel with a longitudinal axis of the volumetric body 21 (FIG. 1)as defined from end face 22 (FIG. 1) to end face 23 (FIG. 1). The ribs35 extend inwardly toward the interior 210 (FIG. 1) of the volumetricbody 21 (FIG. 1) and are disposed non-contiguously in order to defineairflow pathways 350. Thus, air permitted to enter the interior 210(FIG. 1) of the volumetric body 21 (FIG. 1) via the through-holes 30(FIG. 1) may be distributed relatively evenly throughout the interior210 (FIG. 1).

With reference to FIG. 5, the heat exchange elements 40 disposed withinthe interior 210 of the volumetric body 21 include a tubular element 41and fins 42. The tubular element 41 may be disposed between the endfaces 22 and 23 (FIG. 1) to run along the longitudinal axis through theinterior 210 in a back and forth pattern via tube sections and hairpins.A first medium such as coolant fluid (i.e., water) may be directed toflow through the tubular element 41. The tubular element 41 may be asingle, continuous part or multiple separate parts. The fins 42 areformed to define through-holes through which the tubular element 41extends and are disposed to run perpendicularly with respect to thetubular element 41 and the ribs 35 (FIG. 1). Each fin 42 may besubstantially thin and formed of a thermally conductive material such asmetal or metallic alloy by which thermal conduction with respect to thefirst medium is achievable.

The sorbent material 60 may be provided in pellet form (not shown) andis disposed among the heat exchange elements 40 within the interior 210of the volumetric body 21. More particularly, the sorbent material 60may be provided between the fins 42 such that thermal conduction betweenthe first medium, the fins 42 and the sorbent material 60 isfacilitated. This thermal conduction serves to maintain a temperature ofthe sorbent material 60 within a given, predefined range at which thesorbent material 60 is able to relatively efficiently absorb or desorbgases from the air flowing through the airflow pathways 350 (FIG. 4).

With reference back to FIG. 1, the sorbent material 60 may be supportedamong the heat exchange elements 40 and within the interior 210 of thevolumetric body 21 by upper and lower layers of structural features. Theupper layers may include a retainer screen 61 to retain the sorbentmaterial 60 in vertical position and a structural (i.e., aluminum,copper, carbon) foam layer 62 to provide structural support to theretainer screen 61. Neither the retainer screen 61 nor the structuralfoam layer 62 adds any appreciable obstruction to air flow throughoutthe interior 210. In accordance with embodiments, the structural foamlayer 62 may be formed from multiple pieces without substantiallysacrificing structural rigidity. In accordance with further embodiments,the multiple pieces may be aligned such that the ribs 35 extend inbetween the multiple pieces. The structural foam of structural foamlayer 62 may be made from metals, such as aluminum or copper or alloysthereof, or non-metallic materials, such as carbon or silicon carbide.

As shown in FIG. 5, the structural partition walls 80 are disposed amongand substantially in parallel with the fins 42 to run perpendicularlywith respect to the ribs 35 (FIG. 4) and the tubular element 41. As withthe fins 42, the partition walls 80 are formed to define through-holesthrough which the tubular element 41 extends. In accordance withembodiments, the partition walls 80 may be disposed in a longitudinalarray through the interior 210 of the volumetric body 21 with uniform ornon-uniform spacing from one another. Where the partition walls 80 areuniformly spaced from one another, a uniform number of fins 42 may beinterposed between adjacent partition walls 80. Where the partitionwalls 80 are non-uniformly spaced from one another, a non-uniform numberof fins 42 may be interposed between adjacent partition walls 80.

Still referring to FIG. 5, it is seen that the fins 42 have upper andlower edges that define upper and lower planes, P, and that thepartition walls 80 protrude above and below the upper and lower planes,P, respectively. As such, when forces or external loads are applied tothe upper and lower sides 26 and 27 (FIG. 1), the ribs 35 transmit forceto the upper and lower layers of structural features as described aboveand to the partition walls 80 at contact points 81 (see FIG. 4) definedwhere the ribs 35 (FIG. 4) cross the partition walls 80. The transmittedforce may be generated by an external load, such as pressure applied toeither or both of the upper and lower sides 26 and 27 (FIG. 1) and, bytransmitting such force or loading between the upper and lower sides 26and 27 (FIG. 1) from the ribs 35 (FIG. 1) and through the interior 210of the volumetric body 21, the partition walls 80 prevent the fins 42from seeing or experiencing any forces or loads.

Where the forces or external loading is substantial and would crush thefins 42 if not for the partition walls 80, the partition walls 80 serveto protect the fins 42 from crushing effects and tend to increase alifetime of the heat exchanger 10 (FIG. 1).

In accordance with aspects of the invention, the structural foam layers62 (FIG. 4) may be provided with or without the additional structuralsupport of the partition walls 80 and ribs 35 (FIG. 4). In these cases,the forces and external loads applied to the upper and lower sides 26and 27 (FIG. 1) are transmitted to the structural foam layers 62 (FIG.1), which may provide for load absorption that prevents the fins 42 fromseeing or experiencing any detrimental forces or loads. In these cases,a primary purpose of the structural foam is to support the retainerscreen 61 (FIG. 1) where loads on the retainer screen 61 (FIG. 1) areprimarily due to the differential pressure across the sorbent material60.

While the invention has been described in detail in connection with onlya limited number of embodiments, it should be readily understood thatthe invention is not limited to such disclosed embodiments. Rather, theinvention can be modified to incorporate any number of variations,alterations, substitutions or equivalent arrangements not heretoforedescribed, but which are commensurate with the spirit and scope of theinvention. Additionally, while various embodiments of the invention havebeen described, it is to be understood that aspects of the invention mayinclude only some of the described embodiments. Accordingly, theinvention is not to be seen as limited by the foregoing description, butis only limited by the scope of the appended claims.

The invention claimed is:
 1. A heat exchanger, comprising: a framedefining a volumetric body with substantially flat upper and lower sidesthat each has inwardly extending ribs; heat exchange elements disposedwithin an interior of the body; sorbent material disposed among the heatexchange elements within the interior of the body; retainer screensdisposed at upper and lower sides of the heat exchange elements andsorbent material; and structural foam layers provided in multiple piecesrespectively disposed between the ribs and supportively disposed betweenthe retainer screens and the substantially flat upper and lower sides toabsorb loading applied to the retainer screens.
 2. The heat exchangeraccording to claim 1, wherein the body is substantially rectangular. 3.The heat exchanger according to claim 1, wherein the inwardly extendingribs define airflow paths.
 4. The heat exchanger according to claim 1,wherein sidewalls of the frame are formed to define through-holes foradmitting airflow into the interior of the body.
 5. The heat exchangeraccording to claim 1, wherein the heat exchange elements comprise: atubular element through which coolant is directable; and fins runningperpendicularly with respect to the tubular element.
 6. The heatexchanger according to claim 1, wherein the sorbent material comprises aplurality of pellets.
 7. The heat exchanger according to claim 1,wherein the structural foam layers comprise at least one or more ofaluminum, copper, carbon and silicon carbide.
 8. A heat exchanger,comprising: a frame defining a volumetric body with substantially flatupper and lower sides that each has inwardly extending ribs; heatexchange elements disposed within the body and including a tubularelement through which a first medium is directable and fins, the finsbeing oriented perpendicularly with respect to the tubular element;sorbent material disposed among the fins within the interior of thebody; retainer screens disposed at upper and lower sides of each of theheat exchange elements and sorbent material; and structural foam layersprovided in multiple pieces respectively disposed between the ribs andsupportively disposed between the retainer screens and the substantiallyflat upper and lower sides to absorb loading applied to the retainerscreens.
 9. The heat exchanger according to claim 8, wherein the body issubstantially rectangular.
 10. The heat exchanger according to claim 8,wherein the inwardly extending ribs defining airflow paths.
 11. The heatexchanger according to claim 8, wherein sidewalls of the frame areformed to define through-holes for admitting airflow into the interiorof the body.
 12. The heat exchanger according to claim 8, wherein thesorbent material comprises a plurality of pellets.
 13. The heatexchanger according to claim 8, wherein the structural foam layerscomprise at least one or more of aluminum, copper, carbon and siliconcarbide.
 14. A heat exchanger assembly including multiple heatexchangers that each comprise: a frame defining a volumetric body withsubstantially flat upper and lower sides that each has inwardlyextending ribs and that are each configured to register with acomplementary side of an adjacent heat exchanger; heat exchange elementsdisposed within the body and including a tubular element through which afirst medium is directable and fins, the fins being orientedperpendicularly with respect to the tubular element; sorbent materialdisposed among the fins within the interior of the body; retainerscreens disposed at upper and lower sides of the heat exchange elementsand sorbent material; and structural foam layers provided in multiplepieces respectively disposed between the ribs and supportively disposedbetween the retainer screens and the substantially flat upper and lowersides to absorb loading applied to the retainer screens.
 15. The heatexchanger assembly according to claim 14, wherein the body issubstantially rectangular.
 16. The heat exchanger according to claim 14,wherein sidewalls of the frame are formed to define through-holes foradmitting airflow into the interior of the volumetric body.
 17. The heatexchanger according to claim 14, wherein the sorbent material comprisesa plurality of pellets.
 18. The heat exchanger according to claim 14,wherein the structural foam layers comprise at least one or more ofaluminum, copper, carbon and silicon carbide.